Washington (CNN)The Pentagon has rejected a State Department request to deploy a detachment of US Marines to Taiwan to help safeguard the de facto American embassy there, three US officials tell CNN.

The decision to deny the request was made by Secretary of Defense James Mattis last month, according to two of the officials.

One defense official told CNN that prior to the request being rejected, military planners had anticipated the Marines arriving in Taiwan as early as next month.

Asked about the decision, a State Department official told CNN "we do not discuss specific security matters concerning the protection of our facilities or personnel."

US officials told CNN in June that the State Department had sought the deployment of a Marine Security Guard detachment to help bolster security at the new American Institute in Taiwan facility which will house some 450 staff and sits in the outskirts of Taiwan's capital, Taipei.

As part of its "One China Policy," Washington does not formally recognize self-governing Taiwan as an independent country, and therefore the US does not have an official embassy there.

However, the US maintains a de facto embassy in the form of the American Institute, which was established as part of the Taiwan Relations Act of 1979, which governs America's relationship with the island since the US switched its recognition to Beijing.
While reports that Marines could be sent to Taiwan drew a warning from Beijing, a defense official told CNN that the request was rejected due to resource constraint issues and not to avoid irritating the communist government.

The official said that the State Department had not told the Pentagon in advance that the completion of the new facility would require a Marine Security Guard detachment, which contributed to the request's rejection.

The sessional security requirements are now likely to be fulfilled by contractors who are likely more expensive.Tensions between Beijing and the Trump administration have been recently heightened over a range of issues.

President Donald Trump recently accused China of pressuring North Korea to resist denuclearization efforts, and his administration has been involved in tense trade negotiations with Beijing.

Meanwhile the Trump administration has also signaled some increased support for Taiwan, recently recalling America's top diplomats from the Dominican Republic, El Salvador and Panama for consultations over those countries' recent decisions to no longer recognize Taiwan.

__________________
Boats

O Almighty Lord God, who neither slumberest nor sleepest; Protect and assist, we beseech thee, all those who at home or abroad, by land, by sea, or in the air, are serving this country, that they, being armed with thy defence, may be preserved evermore in all perils; and being filled with wisdom and girded with strength, may do their duty to thy honour and glory; through Jesus Christ our Lord. Amen.